The invention relates to a tool for machining workpieces which is designed with separate channels to prevent undesired separation of fluid media being conveyed through the tool.
Tools of the class addressed here are known. They are used, among other things, in connection with machine tools, where a tool insert is clamped manually especially by means of a collet and can be changed and where a coolant/lubricant is supplied preferably inside the tool. To pass the coolant/lubricant through, there is a channel, running essentially in the axial direction, inside the tool. These tools are also operated with the MMS technology (minimum quantity lubrication). To this end, a mixture of air and oil is usually conveyed by way of the channel through the tool up to the actual operating site, the cutting edge. This mixture is produced by atomizing and is conveyed through the channel to the actual operating site. It has been demonstrated that in the case of tools of the generic class an undesired separation or sagging of the mixture of oil and air occurs owing to the length of the channel and owing to the change in direction of the channel.
Therefore, the object of the invention is to provide a tool, which is characterized in that especially when the minimum quantity lubrication technology is applied, an undesired separation and a sagging while operating the tool are largely prevented.
To solve this problem a tool is proposed that comprises structural features including a collet that has a second channel, which is separated from a first channel and runs essentially in the axial direction. Different mediums can be conveyed in the channels, which empty into a mixing and vorticizing chamber. This feature has the advantage that the mediums can be conveyed separately through the collet; and consequently the point of origin of a mixture is, seen in the direction of flow, closer to the actual operating site, thus at the cutting edge. A separation or sagging on the short path from the mixing chamber to the actual operating site is almost totally ruled out.
A preferred embodiment of the tool is characterized in that the second channel also continues in the tool insert. Thus, it is guaranteed that the mixture, comprising different mediums, can be produced in close vicinity to the cutting edge; and hence any undesired separation before the mixture becomes effective is ruled out.
Another preferred embodiment of the tool is characterized in that the continuation of the channels by way of the interfaces-the tool holder collet and/or the collet tool insert-is realized by means of centered pins and/or circumferential ring grooves. This feature enables two channels to pass over the interfaces of the tool parts, which can be rotated in relation to each other when they are in the non-fixed state. Other advantages follow from the other dependent claims.
The invention is explained in detail below with reference to the drawings.